Bleaching of oils.



GEORGE E. DROHN, OF OMAHA, NEBRASKA.

BLEACI-IING OF OILS.

aooxzrs.

No Drawing.

To all whom it may concern Be it known that I, GEORGE F. DROHN, a citizen of the United States, residing in the city of Omaha, in the county of- Douglas and State of Nebraska, have invented certain new and useful Improvements in the Bleaching of Oils, and have described the same in the following specification.

My invention relates to the art of bleaching oils, especially refined cotton seed oils, by abstracting color or coloring matter therefrom, and to bleaching compounds of the class used in that art.

The main object of the invention includes the following particulars, viz: to produce in a convenient, inexpensive and available form a powerful bleaching compound of the specified class; to increase the efliciency of this art; to augment the bleaching effect of the bleaching treatment of oils of this class; to produce a complete and satisfactory bleaching of such oils, been previously refined little or much, and whether they are of high color or otherwise;

and to render possible an economlcal savingoil in the refining of crude oils preparatory to bleaching, To accomplish these results, I combine in my improved bleaching compound as component ingredients thereof, a certain form of carbon and a certain alkaline hydroxid, and treat refined oils with this compound in a special process. Said bleachingcompound is an intimate mixture of charcoal, by preference charcoal of vegetable origin, with an alkaline hydroxid such as sodium hydroxid or potassium hydroxid, the former being preferred for the sake of cheapness. Th1s composition is produced by first dissolvlng a quantity of the hydrfizid in water, by then adding to the solution a larger quantity of any good vegetable charcoal, preferably in comminuted form, the relative quantity of charcoal varying with the condition of the oil to be treated, and being preferably some five to ten times as much by weight as the hydroxid; by then mixing these ingredients thoroughly together, as by agitation in a suitable boiler; by then evaporating the water and expelling the moisture from the mixture; and by then grinding the thoroughly dried residuum to a fine powder, preferably capable of passing through a one-hundredmesh sieve. The described drying of the of chemicals and of mixture is preferably done at a temperature varylng from one hundred. degrees centl- Specification of Letters Patent.

whether they have a quantity of Patented Oct. 110, rare.

Application/filed January 5, 1915. Serial N6. 702;

grade to that producingadull red heat of the product, and 1n a crucible or other receptacle from which atmospheric air and moisture are excluded. I have discovered that this powdered product, whose absorbent particles of charcoal serve as carriers of the commingled hydroxid, has a high and peculiar power of abstracting color from cot- 'tonseed 011 wherein it may be held in suspenslon.

My special process, wherein the described bleaching compoundv is used, may now be described. The oil which isto be treated is first refined to at least a moderate degree by the use of chemicals in any usual or conven- 1ent manner, but with this permissible difference, that by reason of the superior efliciency of'my bleaching process, this preliminary refinement, as well as the quantity, of refinmg materials employed therein, may be less than are usually requisite in preparing oils of this class for bleaching by other methods. The refined oil is then heated to a suitable temperature for bleaching, as for example eighty to one hundred degrees centigrade.

tated together for half an hour, more or less,

while maintained at that temperature. Then the above described bleaching compound, equal in weight to two per cent., more or less, of the agitated mixture, is added thereto. The agitation and heat are then maintained for'half an hour, more or less, and until the color is suitably reduced; when the entire mixture is allowed to rest, the heavier parts settling to the bottom,- and leaving the bleached oil ready to be drawn off for filterings in the usual manner.

In the following illustrative instance this process and this compound were used with the followin result, viz: One hundred pounds of re ned cottonseed oil, having the color 35 yellow 14 red,- as shown by the Lovibond tintometer, was heated to approximately eighty degrees centigrade; four pounds of fullers earth were then added, and the mixture agitated for ten minutes. Then two pounds of the described bleaching compound were added, and the agitation was continued for twenty minutes additional, the temperature being maintained at eighty to one hundred and twenty degrees.

After ten minutes, more or less, allowed for settling, the oil was filtered oil", having the color yellow 2.2 red, by the same tintometer. For comparison, a quantity of the same unbleached oil, having the same initial color, yellow 1 1 red, Was treated according to the ordinary trade formula with six percent. of fullers earth alone, and was then observed to be of the color 20 yellow 5.6 red after bleaching.

From the foregoing description and illustration, it is obvious that my improved bleaching process and bleaching compound are adapted to accomplish the stated main object of the invention in each and all of the particulars above specified.

Although I am aware that certain alkaline hydroxids have been used heretofore for the purpose of abstracting color from cottonseed oils, I am not aware that either sodium hydroxid or any equivalent thereof has been so used in combination with comminuted vegetable charcoal as a Vehicle impregnated therewith.

I claim:

1. The method of producin a bleaching compound for the bleaching 0 oils and the like, which consists in mixing a solution of an alkali metal hydroxid with charcoal, then expelling the moisture and reducing the mixture to a fine powder.

2. The method of producing a bleaching compound for the bleaching of oils and the like, which consists in mixing a solution of an alkali hydroxid with charcoal in com minuted form, then expelling the moisture and reducing the mixture to a fine powder.

3. The method of producing a bleaching compound for the bleaching of oils and the like, which consists in diifusing a solution of an alkali metal hydroxid in and through charcoal, then drying the product at a temperature ranging from 100 centigrade to a dull red heat of the product, and then grinding the dried residuum to a fine powder.

4. The method of producing a bleaching compound for the bleaching of oils and the like, which consists in diffusing a solution of an alkali metal hydroxid in and through charcoal, then drying the product at a temperature ranging from 100 centigrade to a dull red heat of the product, and at the same time excluding the atmospheric air and moisture therefrom, and theh grinding the dried residuum to a fine powder.

In testimony whereof I aflix my signature in presence of two witnesses.

GEORGE F. DROHN. Witnesses F. H. FASTER, J. J. SoLoMoN. 

